Mobile water reclaiming system

ABSTRACT

A vacuum truck for dispensing water into a sewer or similar location and receiving recovered water from the sewer that includes debris to be removed therefrom. The vacuum truck includes a debris tank that receives the recovered water and retains debris removed from the recovered water. A primary and a secondary filter are positioned in the debris tank for separating debris from the recovered water. A water pump draws the recovered water through the secondary filter and provides the water to a tertiary filter that removes smaller debris from the recovered water. The recovered water from the tertiary filter is provided directly to a jetting water pump without being accumulated in a water holding tank. The vacuum truck includes a water storage tank that includes potable water for cleaning the truck or when recovered water is not available from the debris tank.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is based on and claims priority to U.S.Provisional Patent Application Ser. No. 61/751,298 the disclosure ofinch is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present disclosure relates to a mobile water recycling system foruse with vacuum trucks, such as sewer cleaning and hydro-excavationequipment. More specifically, the present disclosure relates to a waterrecycling system that removes debris from recovered sewer water andrecycles the water for continuous use in the sewer cleaning process.

Presently, sewer and catch basin cleaners are available that include alarge suction device for removing debris from within a sewer line. Aspart of the sewer and catch basin cleaner, a water pump system isincluded on the vehicle that creates a high pressure supply of waterthat can be used to clean and remove debris from within the sewer line.As part of this high pressure water cleaning system, a jetting waterpump is used on the machine to create the supply of pressurized water.

Current systems used with sewer and catch basin cleaners include anonboard water tank that stores a supply of water to be used during thecleaning process. Since the size and volume of the onboard water tank islimited, the sewer cleaning and hydro-excavation equipment must berefilled on a periodic basis to allow the unit to continue to cleansewer systems.

Presently, systems exist that allow the water removed from the sewer tobe cleaned and recycled for continuous use in the sewer excavation andcleaning process. Water recycling in the sewer cleaning industry is verycommon in Europe, and there are many water recycling systems on Europeansewer cleaning trucks. However, most of these systems are limited inboth the filtering and amount of water that can be processed during theuse of the equipment. The present disclosure addresses many of thelimitations currently present in sewer cleaning and hydro-excavationunits that use recycled water.

SUMMARY OF THE INVENTION

A vacuum truck, such as a combination sewer and catch basin cleaningtruck sucks up sewage affluent and debris into a debris tank using anonboard vacuum system is disclosed. A water recycling system filters thewater affluent and supplies the filtered water to a high pressure waterpump for sewer jetting work. In accordance With the present disclosure,water recycling is the use of water from a sewer line as the jettingwater to clean the same sewer line. The present disclosure differs fromcurrently available systems based upon the combination and sequence offiltering stages. These stages provide an optimal level of waterfiltration for sewer jetting work, while increasing the robustness ofthe system. The stages of filtration are set forth below.

Primary filtration: A primary filter, such as but not limited to anejector plate in the debris tank separate liquids from large solids. Alldebris and affluent material enters the debris tank on the rear side ofthe primary filter, such as the ejector plate. The primary filter hassmall clearances and passages to allow liquids and only small solids topass to the front side of the ejector plate. The clearances and passagesare adjustable from about 0.060 inch to 0.300 inch, although other sizesare contemplated.

Secondary filtration: A self-cleaning secondary filter including afilter screen is positioned within the inside the debris tank on thefront side of the primary filter. The secondary filter allows liquidsand material having a smaller size than those that were allowed to passthe primary filter to pass. As an example, solid particles less than0.060 inch (0.040 inch to 0.100 inch) can pass the secondary filter. Thesecondary filter preferably includes a filter screen having aself-cleaning internal spray bar to remove material attached to theoutside of the screen.

A solids-handling water pump sucks liquids out of the debris tankthrough the secondary filter. This water pump also pressurizes the waterenough to force the water through a subsequent tertiary filter andbeyond. The flow rate of the water pump is sized to meet the entire flowrate requirement for the jetting water pump plus the flow rate neededfor both self-cleaning filters.

Tertiary filtration: The system includes a tertiary filter, which can bea self-cleaning filter screen. The tertiary filter further removesmaterial from the water. The screen passages of the tertiary filter aretypically 0.006 inch but can range from (0.001 inch to 0.050 inch). Inthe tertiary filter, the water is forced into the inside of acylindrical screen. Screened material builds up on the inside of thescreen and is then removed by a rotating nozzle. The downstream line,the purge line, of the rotating nozzle is routed back into the debristank. This purging may be intermittent or continuous. Liquids passingthrough the screen of the tertiary filter are clean enough to passthrough the jetting water pump and the rest of the system withoutsignificant wear, damage or problems.

Most of the filtered water leaving the tertiary filter is sent directlyto the jetting water pump. In currently available water recyclingsystems, recycled water and filtered water is sent to a holding tank forstorage due to the varying rate of water usage by the jetting waterpump. Some fine material eventually settles in these holding tanks andmust be cleaned frequently.

The present disclosure eliminates the maintenance time needed to cleanthe on-board storage tank by sending the filtered water directly to thejetting water pump. The system includes a potable water tank that isutilized on the sewer cleaner truck for times when water recycling isnot used, or when there is not enough liquids in the debris tank forrecycling to occur. A check valve on this water storage tank allowspotable water to exit the tank, but recycled water cannot enter thepotable water tank. This check valve also guarantees the jetting waterpump will not run out of water when there is not enough liquids in thedebris tank.

The rest of the filtered water leaving the tertiary filter is routedback into the debris tank and is used in the spray bar of the secondaryfilter. In this manner, the flow rate required by the jetting water pumpmay vary (from 50 to 120 gpm), and excess filtered water will simply bereturned to the debris tank where is can further improve the system byfurther cleaning the secondary filter.

Another possible embodiment of this invention includes all of the aboveexcept without the primary filtration (ejector plate). In such anembodiment, the secondary filter is positioned in the debris tank andprovides the first level of filtration. In such an embodiment, thescreens of the secondary filter are cleaned with a self-cleaning spraybar that receives a supply of pressurized water.

The present disclosure could also be scaled down to provide waterrecycling on a hydro-excavation truck which uses much lower flow rates(3 to 25 gpm).

The present disclosure also differentiates itself from other systems bybeing generally maintenance free. This feature is achieved by utilizingtwo self-cleaning filters that use the water pressure from the system toperform the cleaning and purging.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the best mode presently contemplated of carryingout the disclosure. In the drawings:

FIG. 1 is a depiction of a vacuum truck, such as a sewer and catch basincleaner, that incorporates the system of the present disclosure; and

FIG. 2 is a schematic illustration of the operating system of thepresent disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

A vacuum truck, such as a sewer and catch basin cleaning truck 10, isshown in FIG. 1. Although a sewer and catch basin cleaning truck 10 isshown in FIG. 1, the system of the present disclosure could be used withother types of vacuum trucks, such as hydro excavators, liquid vacuumtrucks or industrial vacuum loaders. The sewer cleaning truck 10 shownin FIG. 1 includes an extendable suction hose 12 that removes debrisfrom within a sewer and stores the removed debris within an onboarddebris tank 14. The cleaning truck further includes a water pump systemthat directs a high pressure flow of water into the sewer to loosendebris within the sewer and direct the loosened debris toward thesuction hose 12. An example of such a cleaning truck is the Camel® soldby Super Products of New Berlin, Wis. However, it should be understoodthat other types of vacuum trucks and systems could utilize the waterrecycling system of the present disclosure.

As illustrated in FIG. 2, the cleaning truck includes a debris tank 14that receives the supply of recovered water including solid materialdebris withdrawn from the sewer by the suction hose. The debris tank 14is mounted onto the rear of the vehicle and is used to store the solidmaterial reclaimed from the sewer. The solid material recovered from thesewer can include large, heavy objects such as stones, bricks andsimilar debris as well as light weight, floating objects such as treebranches, wood, floating debris and other similar debris. The debrisrecovered from the sewer is drawn into the debris tank 14 entrained inthe flow of water from the sewer.

The debris tank 14 includes a primary filter 16 that is used to separatethe larger solid particles from the recovered water drawn into thedebris tank 14. In the embodiment shown in FIG. 2, the primary filter 16is an ejector plate 18 that extends across the entire open interior ofthe debris tank 14. The edges of the ejector plate 18 are spaced fromthe inner walls of the debris tank to define a small clearancepassageway 21 that allows liquids and only very small solids to passfrom the back area 20 to the front area 22 of the debris tank 14.Additional passages may be added to the ejector plate 18 to furthercontrol the amount and filtration quality of the recovered water passingfrom the back area 20 to the front area 22. In the embodiment shown, theclearance between the outer edges of the ejector plate 18 and the innerwall of the debris tank 14 is adjustable between 0.060 inches to 0.300inches. The adjustable clearance between the ejector plate 18 and thesidewalls of the debris tank 14 limits the size of solid materials thatcan pass into the front area 22 of the debris tank 14.

The liquid contained within the front area 22 thus includes particlesthat are small enough to pass around the outer edge of the ejector plate18. In accordance with the present disclosure, a secondary filter 24 islocated in the front area 22. In the preferred embodiment of thedisclosure, the secondary filter 24 is a self-cleaning filter screenthat is positioned within the front area 22. The secondary filter 24 issized to allow liquids and materials having a size less than 0.060inches (0.040 inches to 0.100 inches) to pass through the filter. In theembodiment shown, the secondary filter 24 includes a self-cleaninginternal spray bar that removes materials attached to the outside of thescreen to continuously clean the screen during the filtration process.As an example, the secondary filter 24 can be a self-cleaning suctionscreen filter, such as commercially available from VAF FiltrationSystems. Although a specific type and size of secondary filter 24 isdisclosed, it should be understood that other types and sizes ofsecondary filters 24 could be used while operating within the scope ofthe present disclosure. The secondary filter 24 should be sized toremove smaller solids from the supply of fluid as compared to theprimary filter 16.

Although the embodiment shown in the drawing figures include both aprimary filter 16, such as the ejector plate 18, and a secondary filter24, it is contemplated that the ejector plate 18 could be eliminated. Insuch an embodiment, the secondary filter 24 would limit the size of thematerial that leaves the debris tank 14. If the ejector plate 18 iseliminated, it becomes more important that the secondary filter 24includes a self-cleaning mechanism since larger particles will becomeattached to the outside of the screen of screens included in thesecondary filter.

As illustrated in FIG. 2, a solids handling water pump 26 is connectedto the secondary filter 24 through a suction line 28. Operation of thewater pump 26 creates a flow of water from the front area 22 through thesuction line 28. The flow of water in the suction line 28 is drawnthrough the secondary filter 24 and thus draws liquid from within thefront area 22. In the embodiment illustrated, the water pump 26 is acentrifugal water pump that is operable to create a flow of 150 gallonsper minute of fluid. The water pump 26 is selected such that the pumpcan handle the small solids being drawn through the secondary filter 24.The flow rate of the water pump 26 is selected to meet the entire flowrate requirements for the jetting water pump 30, which will be describedin much greater detail below. The water pump 26 is a self-regulatingpump, such as a centrifugal pump, that self-regulates the output flow tomatch the flow rate demand of the jetting water pump 30 without overpressurizing the system.

Fluid from the water pump 26 is directed to a three-way ball valve 32that can be selectively positioned to either direct water back to thesewer through return line 34 or to direct the flow of water to atertiary filter 36 through an inlet line 38. In the embodiment shown,the tertiary filter 36 is a self-cleaning filter screen that furtherremoves materials from the water initially withdrawn from the front area22 of the debris tank. The tertiary filter 36 includes a filteringscreen having passageways in the range of 0.006 inches although othersizes are contemplated. As an example, the tertiary filter 36 can be aV-200PA automatic screen filter available from VAF Filtration Systems.Although a specific type and size of tertiary filter 36 is disclosed, itshould be understood that other types and sizes of tertiary filters 36could be used while operating within the scope of the presentdisclosure. The tertiary filter 36 should be sized to remove smallersolids from the supply of fluid as compared to the secondary filter 24.

In the tertiary filter 36, water in the inlet line 38 is forced into acylindrical screen which removes solid particles from the flow of water.The screened material builds up on the inside of the screen and isremoved by a rotating nozzle within the tertiary filter 36. The smallparticles of material removed by the tertiary filter 36 are returned tothe debris tank 14 through a purge line 40. The purge line 40 includes apurge valve 42 that controls the flow of the accumulated solids andfluid from the tertiary filter 36. The purge valve 42 may be manually orautomatically operated on an intermittent or continuous basis. In asimplified embodiment, the purge valve 42 can be replaced by a flowrestriction device positioned between the tertiary filter 36 and thedebris tank 14 to regulate the purge flow rate. In such an embodiment,the preferred flow restriction is determined simply by the diameter ofthe purge line 40.

The water that has passed through the tertiary filter 36 includes solidparticles that are small enough such that the flow of water from thetertiary filter can be supplied directly to the jetting water pump 30.The flow of filtered fluid originally drawn from the debris tank 14 canbe used in the jetting water pump of the cleaning truck 10 withouthaving to draw water from the onboard water holding tank 52. Thecombination of the three filters 18, 24 and 36 allows the cleaning truck10 to continually recycle water from within the debris tank 14 and nothave to rely upon the fixed volume of the water holding tank 52.

As illustrated in FIG. 2, water leaving the tertiary filter 36 throughoutlet line 44 can also be returned to the secondary filter 24 through areturn line 46. Since the water in the return line 46 is pressurizedthrough operation of the water pump 26, the water in the return line 46can be used to clean the secondary filter 24.

The remaining portion of water from the outlet line 44 of the tertiaryfilter 36 is supplied directly to the jetting water pump 30 through thewater supply line 48. The jetting water pump 30 can be any one of variesavailable water pumps that operate to create a pressurized supply ofwater that is directed into the sewer for further cleaning. The waterfrom the jetting water pump 30 is again withdrawn from the sewer, alongwith debris, by the suction hose and stored in the debris tank 14.

The water supply line 48 is connected to the jetting water pump 30through a connection point 50. The connection point 50 is also coupledto a fresh water supply line 51 that is in fluid communication with apotable water holding tank 52 through a one-way check valve 54. Theone-way check valve 54 prevents water in the water supply line 48 comingfrom the tertiary filter 36 from entering into the water holding tank52. The water holding tank 52 includes a supply of potable water that isloaded onto the cleaning truck 10 and carried with the truck 10. Theone-way check valve 54 can be opened to allow the jetting water pump 30to selectively receive fresh water from the water holding tank 52 forcleaning the truck 10 and its internal components after use in cleaninga sewer. In accordance with the present disclosure, the water in thewater supply line 48 coming from the tertiary filter 36 is the primarysource of water for the jetting water pump 30.

As can be understood in FIG. 2, when the jetting water pump 30 is beingused to clean sewers, the supply of water used by the jetting water pump30 comes directly from the tertiary filter 36 without being sent to anyholding tank. Since small particles of solids can exist within the flowof water in the supply line 48, the lack of a water holding tank for thefiltered water eliminates the need for maintenance time in cleaning thewater holding tank 52. The supply of water contained in the waterholding tank 52 can be utilized on the cleaning truck 10 for times whenwater recycling is not used or when there is not enough liquid in thedebris tank 14 for recycling to occur.

The jetting water pump 30 typically includes a flow rate that can varyfrom between 50-120 gallons per minute. Since the solid handling waterpump 26 is sized to provide 150 gallons per minute, the excess waterbeing withdrawn from the debris tank 14 by the water pump 26 is eitherdiverted back to the debris tank 14 through the secondary filter 24 orthrough the purge line 40. The jetting water pump 30 draws all of thewater needed during operation from the recycling system including thethree stages of filtration described.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to make and use the invention. The patentable scope of the inventionis defined by the claims, and may include other examples that occur tothose skilled in the art. Such other examples are intended to be withinthe scope of the claims if they have structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent structural elements with insubstantial differences from theliteral languages of the claims.

We claim:
 1. A vacuum truck for dispensing water and receiving recoveredwater including debris to be removed therefrom, comprising: a debristank; a suction hose coupled to the debris tank to direct the recoveredwater including the debris into the debris tank; a primary filterpositioned within the debris tank to separate debris smaller than afirst size from the recovered water; a secondary filter positionedwithin the debris tank to receive the recovered water from the primaryfilter to separate debris smaller than a second size from the recoveredwater; a tertiary filter positioned to receive the recovered water fromthe secondary filter to separate debris smaller than a third site fromthe recovered water; and a jetting water pump that receives therecovered water directly from the tertiary filter to dispense therecovered water.
 2. The vacuum truck of claim 1 further comprising awater pump operable to draw the recovered water through the secondaryfilter and to supply the recovered water at pressure to the tertiaryfilter.
 3. The vacuum truck of claim 2 wherein a flow rate of the waterpump is greater than a flow rate of the jetting water pump.
 4. Thevacuum truck of claim 2 further comprising a return line coupled to anoutput of the tertiary filter to return a portion of the recovered waterto the secondary filter to clean the secondary filter.
 5. The vacuumtruck of claim 1 further comprising a water holding tank mounted to thecleaning truck to receive a supply of portable water, wherein the waterholding tank is coupled to the jetting water pump.
 6. The vacuum truckof claim 5 further comprising a one-way valve positioned between a watersupply line extending from the tertiary filter and the water holdingtank to prevent the flow of recovered water into the water holding tank.7. The vacuum truck of claim 1 further comprising a purge linepositioned between the tertiary filter and the debris tank to directaccumulated debris from the tertiary filter to the debris tank.
 8. Thevacuum truck of claim 7 further comprising a purge valve positionedwithin the purge line, wherein the purge valve controls the flow of theaccumulated debris from the tertiary filter to the debris tank.
 9. Thevacuum truck of claim 1 wherein the first size of debris is larger thanthe second size of debris and the second size of debris is larger thanthe third size of debris.
 10. A water reclaiming system for use on atruck having a debris tank that receives recovered water includingdebris, the system comprising: a primary filter positioned within thedebris tank to separate debris smaller than a first size from therecovered water: a secondary filter positioned within the debris tank toreceive the recovered water from the primary filter to separate debrissmaller than a second size from the recovered water; a tertiary filterpositioned to receive the recovered water from the secondary filter toseparate debris smaller than a third size from the recovered water; anda jetting water pump that receives the recovered water directly from thetertiary filter to dispense the recovered water.
 11. The waterreclaiming system of claim 10 further comprising a water pump operableto draw the recovered water through the secondary filter and to supplythe recovered water to the tertiary filter.
 12. The water reclaimingsystem of claim 11 wherein a flow rate of the water pump is greater thana flow rate of the jetting water pump.
 13. The water reclaiming systemof claim 11 further comprising a return line coupled to an output of thetertiary filter to return a portion of the recovered water to thesecondary filter to clean the secondary filter.
 14. The water reclaimingsystem of claim 10 further comprising a water holding tank mounted tothe cleaning truck to receive a supply of portable water, wherein thewater holding tank is coupled to the jetting water pump.
 15. The waterreclaiming system of claim 14 further comprising a one-way valvepositioned between a water supply line extending from the tertiaryfilter and the water holding tank to prevent the flow of recovered waterinto the water holding tank.
 16. A vacuum truck operable to dispensewater into a sewer and recover water from the sewer including debris,comprising: a debris tank; a suction hose coupled to the debris tank todirect the recovered water from the sewer including the debris into thedebris tank; a secondary filter positioned within the debris tank toreceive the recovered water, wherein the secondary filter includes ascreen that separates debris smaller than a second size from therecovered water; a water pump operable to draw the recovered waterthrough the screen of the secondary filter; a tertiary filter positionedto receive the recovered water from the water pump, wherein the tertiaryfilter separates debris smaller than a third size from the recoveredwater; a return line coupled to an output of the tertiary filter toreturn a portion of the recovered water to clean the screen of thesecondary filter; a jetting water pump positioned to receive therecovered water from the tertiary filter such that the recovered wateris dispensed by the jetting water pump; and a water holding tank mountedto the cleaning truck to receive a supply of portable water, wherein thewater holding tank is coupled to the jetting water pump to selectivelysupply the potable water to the jetting water pump.
 17. The vacuum truckof claim 16 further comprising a primary filter positioned within thedebris tank to separate debris smaller than a first size from therecovered water, wherein the primary filter includes an ejector platepositioned within the debris tank, wherein the recovered water passesfrom a first side of the ejector plate to a second side of the ejectorplate to separate debris from the recovered water and wherein thesecondary filter is positioned on the second side of the ejector plate.18. The vacuum truck of claim 16 further comprising a one-way valvepositioned between the water supply line from the tertiary filter andthe water holding tank to prevent the flow of the recovered water intothe water holding tank.
 19. The vacuum truck of claim 16 wherein theflow rate of the water pump is greater than the flow rate of the jettingwater pump.
 20. The vacuum truck of claim 16 further comprising a purgeline positioned between the tertiary filter and the debris tank todirect accumulated debris from the tertiary filter to the debris tank.